Downhole apparatus and method

Abstract

A downhole apparatus comprising a body configured to be coupled to a production tubular and an upper opening and a lower opening. First and second flow paths are provided between the upper opening and the lower opening in the body, and a flow diverter is arranged to direct downward flow through the body towards the second flow path and away from the first flow path. A filter device in the second flow path filters or collects solid particles in the second flow path from passing out of the lower opening of the apparatus. The apparatus has particular application to artificial lift hydrocarbon production systems, and may be installed above a downhole pump in a production tubing to prevent solids from settling on the pump during pump shutdown. Embodiments for use with ESPs and PCPs are described.

The invention claimed is: 
     
       1. A downhole production apparatus comprising:
 an outer tubular having an upper opening and lower opening, the outer tubular configured to be assembled into a production string above a downhole production pump; 
 an inner tubular extending at least partially along the inside of the outer tubular, the inner tubular having a wall with at least one passageway; and 
 annular space separating at least part of the outer tubular and at least part of the wall of the inner tubular, wherein the annular space is arranged to collect downward moving solid particles that have been directed away from the inner tubular and toward the annular space; 
 a flow diverter arranged to direct downward moving solid particles toward the annular space and away from the inner tubular; 
 wherein the at least one passageway extends from an inside of the inner tubular to the annular space such that fluid flowing upwardly into the inner tubular flows through the wall of the inner tubular and into the annular space, thereby causing solid particles that have been collected to be carried out of the annular space. 
 
     
     
       2. The apparatus of  claim 1 , further comprising at least one opening, wherein the at least one opening permits fluid flowing upwardly in the inner tubular to reach the upper opening of the outer tubular even if upward flowing fluid cannot flow through the at least one passageway in the wall of the inner tubular due to an accumulation of collected solid particles. 
     
     
       3. The apparatus of  claim 1 , wherein the at least one passageway comprises multiple passageways in the wall of the inner tubular, the multiple passageways arranged such that fluid flowing upwardly into the inner tubular flows out the multiple passageways and into the annular space, thereby causing solid particles that have been collected to be progressively carried out of the annular space. 
     
     
       4. The apparatus of  claim 1 , wherein the at least one passageway comprises a first passageway and a second passageway in the wall of the inner tubular, the first passageway positioned adjacent a first end of the wall and the second passageway positioned adjacent an end opposite of the first end such that the second passageway permits fluid flowing upwardly in the inner tubular to reach the upper opening in the outer tubular even if fluid cannot flow through the first passageway in the wall of the inner tubular due to an accumulation of collected solid particles. 
     
     
       5. The apparatus of  claim 1 , further comprising one or more holes arranged between a main flow path through the apparatus and a lower part of the annular space, the one or more holes arranged to receive upward flow of fluid from the main flow path and to stimulate upward flow at a bottom of the annular space, further assisting with carrying collected solids away from the lower part of the annular space. 
     
     
       6. The apparatus of  claim 1 , wherein the at least one passageway comprises a slot. 
     
     
       7. The apparatus of  claim 6 , wherein the slot has a dimension of approximately 0.5 millimeters. 
     
     
       8. The apparatus of  claim 6 , wherein the slot is a laser cut slot. 
     
     
       9. The apparatus of  claim 1 , wherein the at least one passageway comprises two or more slots having different orientations. 
     
     
       10. The apparatus of  claim 9 , wherein the two or more slots each have a dimension of approximately 0.5 millimeters. 
     
     
       11. The apparatus of  claim 9 , wherein the two or more slots are laser cut slots. 
     
     
       12. The apparatus of  claim 1 , further comprising a mesh or screen disposed over the at least one passageway. 
     
     
       13. The apparatus of  claim 1 , further comprising a downhole production pump, wherein the downhole production pump is an electric submersible pump (ESP) or progressive cavity pump (PCP) coupled beneath the lower opening of the tubular housing. 
     
     
       14. The apparatus of  claim 1 , wherein the flow diverter comprises a valve. 
     
     
       15. The apparatus of  claim 14 , further comprising at least one opening, wherein the at least one opening permits fluid flowing upwardly in the inner tubular to reach the upper opening of the outer tubular even if upward flowing fluid cannot flow through the at least one passageway in the wall of the inner tubular due to an accumulation of collected solid particles. 
     
     
       16. The apparatus of  claim 14 , wherein the at least one passageway comprises multiple passageways in the wall of the inner tubular, the multiple passageways arranged such that fluid flowing upwardly into the inner tubular flows out the multiple passageways and into the annular space, thereby causing solid particles that have been collected to be progressively carried out of the annular space. 
     
     
       17. The apparatus of  claim 14 , wherein the at least one passageway comprises a first passageway and a second passageway in the wall of the inner tubular, the first passage way positioned adjacent a first end of the wall and the second passageway positioned adjacent an end opposite of the first end such that the second passageway permits fluid flowing upwardly in the inner tubular to reach the upper opening in the outer tubular even if fluid cannot flow through the first passageway in the wall of the inner tubular due to an accumulation of collected solid particles. 
     
     
       18. The apparatus of  claim 14 , further comprising one or more holes arranged between a main flow path through the apparatus and a lower part of the annular space, the one or more holes arranged to receive upward flow of fluid from the main flow path and to stimulate upward flow at a bottom of the annular space, further assisting with carrying collected solids away from the lower part of the annular space. 
     
     
       19. The apparatus of  claim 14 , wherein the at least one passageway comprises a slot. 
     
     
       20. The apparatus of  claim 19 , wherein the slot has a dimension of approximately 0.5 millimeters. 
     
     
       21. The apparatus of  claim 19 , wherein the slot is a laser cut slot. 
     
     
       22. The apparatus of  claim 14 , wherein the at least one passageway comprises two or more slots having different orientations. 
     
     
       23. The apparatus of  claim 22 , wherein the two or more slots each have a dimension of approximately 0.5 millimeters. 
     
     
       24. The apparatus of  claim 14 , further comprising a mesh or screen disposed over the at least one passageway. 
     
     
       25. The apparatus of  claim 22 , wherein the two or more slots are laser cut slots. 
     
     
       26. The apparatus of  claim 14 , further comprising a downhole production pump, wherein the downhole production pump is an electric submersible pump (ESP) or progressive cavity pump (PCP) coupled beneath the lower opening of the tubular housing. 
     
     
       27. A downhole apparatus for a production tubing, the apparatus comprising:
 a tubular having an upper opening and a lower opening, and defining a first flow region between the upper opening and the lower opening, 
 wherein the tubular is configured to be assembled into an outer tubular in a production string above a downhole production pump such that a second flow region is formed in a space between the first flow region and a wall of the outer tubular after assembly into the outer tubular, the second flow region being arranged to collect downward moving solid particles; 
 a flow diverter adjacent the upper end of the tubular configured to direct solid particles moving downwardly in the outer tubular away from the first flow region; 
 one or more passageways extending through a wall of the tubular, the one or more passageways arranged such that when the tubular is assembled into an outer tubular upward flowing fluid through the first flow region in an upward direction causes fluid flow in the second flow region, which carries collected solid particles out of the second flow region. 
 
     
     
       28. The apparatus of  claim 27 , wherein the one or more passageways comprises a slot. 
     
     
       29. The apparatus of  claim 28 , wherein the slot has a dimension of approximately 0.5 millimeters. 
     
     
       30. The apparatus of  claim 28 , wherein the slot is a laser cut slot. 
     
     
       31. The apparatus of  claim 27 , wherein the one or more passageways comprises two or more slots having different orientations. 
     
     
       32. The apparatus of  claim 31 , wherein the two or more slots each have a dimension of approximately 0.5 millimeters. 
     
     
       33. The apparatus of  claim 31 , wherein the two or more slots are laser cut slots. 
     
     
       34. The apparatus of  claim 27 , further comprising a mesh or screen disposed over the one or more passageways. 
     
     
       35. The apparatus of  claim 27 , further comprising a downhole production pump, wherein the downhole production pump is an electric submersible pump (ESP) or progressive cavity pump (PCP) coupled beneath the lower opening of the tubular housing. 
     
     
       36. The apparatus of  claim 27  wherein the flow diverter comprises a valve. 
     
     
       37. The apparatus of  claim 36 , wherein the one or more passageways comprises a slot. 
     
     
       38. The apparatus of  claim 37 , wherein the slot has a dimension of approximately 0.5 millimeters. 
     
     
       39. The apparatus of  claim 37 , wherein the slot is a laser cut slot. 
     
     
       40. The apparatus of  claim 36 , wherein the one or more passageways comprises two or more slots having different orientations. 
     
     
       41. The apparatus of  claim 40 , wherein the two or more slots each have a dimension of approximately 0.5 millimeters. 
     
     
       42. The apparatus of  claim 40 , wherein the two or more slots are laser cut slots. 
     
     
       43. The apparatus of  claim 36 , further comprising a mesh or screen disposed over the one or more passageways. 
     
     
       44. The apparatus of  claim 36 , further comprising a downhole production pump, wherein the downhole production pump is an electric submersible pump (ESP) or progressive cavity pump (PCP) coupled beneath the lower opening of the tubular housing. 
     
     
       45. The apparatus of  claim 27 , wherein the tubular is assembled into an outer tubular in a production string above a downhole production pump, thereby forming a second flow region in a space between the first flow region and a wall of the outer tubular. 
     
     
       46. A method of forming a hydrocarbon production system, the method comprising;
 assembling a downhole apparatus according to  claim 27  into a production tubing above a downhole production pump. 
 
     
     
       47. A downhole production system comprising:
 a production string in a hydrocarbon formation; 
 the apparatus according to  claim 1  assembled into the production string; and 
 an electrical submersible pump (ESP) or progressive cavity pump (PCP) assembled into the production string, beneath the apparatus. 
 
     
     
       48. A downhole production system comprising:
 a production string in a hydrocarbon formation; 
 the apparatus according to  claim 27  assembled into the production string; and 
 an electrical submersible pump (ESP) or progressive cavity pump (PCP) assembled into the production string, beneath the apparatus. 
 
     
     
       49. The system of  claim 48 , wherein the flow diverter of the apparatus comprises a valve. 
     
     
       50. A method for washing away collected solid particles from a downhole apparatus, the method comprising:
 operating a downhole production pump, thereby causing fluid to flow upwardly into a first flow region of the downhole apparatus and induce fluid flow in a second flow region of the downhole apparatus via at least one passageway extending through an inner tubular wall separating the first flow region from the second flow region, the induced flow further causing collected solid particles that were directed toward the second flow region and away from the first flow region when the downhole production pump was shutdown to move upwardly, thereby washing collected solid particles from the downhole apparatus. 
 
     
     
       51. The method of  claim 50 , further comprising causing the fluid to flow up the inner tubular and out of a flow diverter, the flow diverter comprising a valve. 
     
     
       52. The method of  claim 50 , wherein the induced flow causes the collected solid particles to be progressively washed from the second flow region. 
     
     
       53. The method of  claim 50 , wherein the downhole production pump is an electrical submersible pump (ESP) or progressive cavity pump (PCP). 
     
     
       54. The method of  claim 50 , wherein the at least one passageway comprises a plurality of slots along the inner tubular wall. 
     
     
       55. The method of  claim 54 , wherein at least one of the plurality of slots has a dimension of approximately 0.5 millimetres. 
     
     
       56. The method of  claim 54 , wherein at least two of the plurality of slots have different orientations. 
     
     
       57. The method of  claim 54 , wherein the plurality of slots are laser cut slots.